ARPCache Viewer - Version 1.01.01 ARPCache is a secret, undocumented section of the registry used to store information for Add/Remove Program items in the latest versions of Windows. If you open Add/Remove Programs in the newer versions of Windows, you will notice that certain information has been added, such as, size, frequency of use, and last used on. This tool allows you to see what is in your ARPCache and lets you remove items from it.